Fluid-actuated rotary tool



F. A. JIMERSON. FLUID ACTUATED ROTARY TOOL.

APPLICATloN .flLEn sEPT.1.192o.

1,385, 1 84. Patented July 19, 1921.

' 2 sHEETs-sHE`ET 1.

F. A. IIMERSON. FLUID ACTUATED ROTARY TOOL.

APPLICATION FILED SEPT. I, 1920.

Patented .lIII'Iy 19, 1921.

UNITED STATES PATENT oEFicE.

FRANCIS A. JIMERSON, OF ATHENS, PENNSYLVANIA, ASSIGNGR T0 N'GERSOLL-- RAND COMPANY, 0F JERSEY CITY, :NEW JERSEY, A, CORPORATION OF NEW JERSEY.

FLUID-ACTUATED ROTARY "IQOL Specification of Letters Patent.

Patented July 19, 1921.

To all 'whom it may concern:

Be it known that I, FRANCIS A. JTMERsoN, a citizen of the United States, residing at Athens, county of Bradford, and State of Pennsylvania, have invented a certain new and useful Improvement in Fluid-Actuated Rotary Tools, of which the following is a specification accompanied by drawings.

This invention relates to fluid actuated, rotary tools, such as drills, grinders, and the like, but more particularlyto such a tool, operated by a motor provided with. a plu-u rality of radially arranged cyiinders havingl pistons connected to a common crank pin ony a longitudinally extending crank, for imparting rotation to a drill, emery Wheel on other operative part to be actuated.

The primary objects of the invention are to increase the speed of the machine with a. given motor of the type referred to, relieve the crank' and connected parts of undue strain, and prolong the life of the crank and other operative parts of the machine.

Another important object is to shorten the motive fluid passages leading to the cylin-i ders as much as practically possible and reduce the clearance required between `the cylindex-s and the tool case.

A further object is to carry the exhaust irom the cylinders past the live air ports in asimple and convenient manner which avoids possible interference or leakage between the live and, exhaust air ports and passages.

To these and other ends which will appear, the invention consists of the features of construction, arrangement of parts and combinations of elements substantially as hereinafter fully described and claimed in this specification and Shown in the accompanying drawings in which- Figure 1 is a longitudinal Sectional elevation of a rotary drill selected as a type of tool to illustrate the invention,

Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 1 looking in the direction of the arrows, and

Fig. 3 isa similar view on the line 3--3 of Fig. 1 looking'inthe direction of the arrows, which indicate that the view is taken in the `opposite direction from that of eferring to the drawings, the case A is provided in this instance with an enlarged chamber B at its rearward 'portion within which the radially arranged cylinders C, D

and E extend. There may be any desired number of these cylinders arranged singly or in pairs but in this instance l have shown three cylinders for purposes of illustration. The cylinders in this instance are single acting and are preferably removably connected to the case in any suitable or desired manner as by means of cylinder cap screws (not shown). The pistons F reciprocating in the cylinders are provided with. suitable connecting rods G suitably connected to a common crank pin H on a longitudinally extending crank J operatively connected by suitable gearing at the front end of the machine to drive the rotary drill bit l carried in the chuck L adapted to be connected. to the spindle 0.

.The supply of' motive fluid to the machine is controlled by the usualthrottle lever P connected to actnate the throttle valve Q; in the handle lt which may' be connected to the casein any suitable manner as by means of handle cap screws (not shown). Any suitable throttle valve may be provided and as the operation'ot this valve is obvious and forms no part of the present invention, it will not be further described. y

ln assembling the connecting rods G on the crank pin H, a connecting rod sleeve S is placed over the crank pin and connecting rod rings T are placed over the ends of the connecting rods and a washer U and crank pin screw V hold the parts on the pin. The crank is preferably provided with an offset extension W to which a counterweight X may be suitably fastened.

The case is provided with a reduced bore Y and the motive fluid supply passage Z in the handle and case leads to an admission port o; in said bore intermediate the length ofthe bore. Motive fluid passages t connect the cylinders with combined supply and exhaust ports c located in the case rearwardly of the admission port a, so that the passages b are as short as conveniently and practicably possible and the necessary clearance between the cylinders and the case is materially reduced. The motive fluid passes alternately in both directions in the passages b for supply and exhaust and by making these passages comparatively short the speed of tie motor is increased and better eiiiciency is obtained. The case A is also providedwith an exhaust'port Z communieating with the smaller bore Y from which the exhaust passes through the exhaust chamber e to the atmospheric port f. This exhaust port d may be located in any convenient position but ispreferably forward of the admission port a as a convenient means ofbringing the exhaust to the front end of the machine.

A main valve bushing g is inserted in the bore Y of the case, to form a tight it and this main bushing g is formed with supply orts h registering with the ports c. The bushing g is also provided with an exhaust porty j at its forward end and an annular passage lc in the interior of the bushing intermediate the supply ports h and the exhaust port j, which passage c communicates with the main-supply passage Z in the case.

The crank J as shown extends through the main valve bushing g and is provided with a hollow bore or portion o lying within the bushing g. The periphery of the crank is provided with a longitudinal passageway in the form ofa groove or depression p, adapted to connect the annular groove lv in the valve bushing g successively with the combined supply and exhaust ports h so that motive iiuid is supplied and distributed to the cylinders of the motor. The crank is also provided with a rearward port g cooperating with the ports it in the bushing for ermitting the cylinders to exhaust into the 'ollow bore of the crank andthence throughl the exhaust port 1' to the main exhaust of the machine. By exhausting the c linders into the interior of the crank and t ence to the forward portion of the crank, the exhaust is carried past the live air ports supplying motivefluid to the cylinders but without interference with said ports or with the passages leading thereto and therefrom.

The crank should5 be a substantially close fit in the'valve bushing g and'in order to take the strain of the rotating parts from the valve bushing, anti-friction bearings are provided for each end of the crank in the case beyond the ends of the bushing. With a high speed motorsuch as the motor disclosed herein, the bearing construction provided prolongs the life of the crank and valve bushin These anti-friction bearings are preferabl in the form of ballbearings. -Th'e crank en bearing s at the inner end is preferably provided with the bearing linter t, and the bearing u at the forward end of the crank forms both a crank and spindle bearing and is provided with the liner lv.

The crank is provided with the crank pinion w meshing with the gear 1/ formed on the spindle O and the spindle preferably rotates within the s indle bushing a within- `the gear case 2 suita ly secured to the front end of the case A as by means of the cap screws 3 .or other fastening devices. A spindle bearlng stud 4 is supported from the case A witghin the bushing 5 and carries the ball bearing 6 for the spindle gear y. It is however to be understood that any suitable or desirable form of driving connections may be provided between the crank and the spindle, the connections shown having proved satisfactory and efficient for a high speed tool.

In the operation of the machine, motive fluid, as air under pressure, is supplied through the supply passage Z under the control of the throttle valve Q and throttle lever P, and thelive air passes around the annular passage lc in the bushing g, through the longitudinal groove p in the crank to one of the motive fluid passage ways b leading to a cylinder. In the drawings, the parts are in such relative positions that admission is about to take place to the cylinder C as the drawings are viewed, the cylinder D is exhausing through the hollow bore of the crank and the cylinder E is at cut-off and on the expansion stroke. As the crank rotates this cycle of operations is repeated in succession for the cylinders.

I claim? l. In a rotary tool, the combination of a case, a fluid actuated motor having a plurality of radially arranged cylinders in said case, a forwardly extending crank connected to be driven by said motor and having a hollow portion, a valve bushing in the case over said Ahollow portion of the crank, a motive fluid supply passage in the case leading to an admission port located at a point intermediate the length of the bushing, motive fluid passages leading from the cylinders to supply ports in the bushing located rearwardly of the said admission'port` an exhaust port in the bushing. a peripheral passageway in the crank for controlling the distribution of motive fluid4 to the passages leading to the cylinders. and ports in the crank for permitting the cylinders to exhaust throuIgh the hollow portion of the crank.

2. n a rotary tool, the combination of a case, a fluid actuated motor having a plurality of radially arranged cylinders in said case, a forwardly extending crank connected to be driven by said motor and having a hollow portion, a valve bushing over said-hollow portion of the cra-nk, anti-friction bearings in the case for the forward and rearward ends of said crank beyond the ends of the bushing, motive Huid passages in the case leading from the cylinders to' supply ports in the rearward ends of the bushing, an exhaust port in the forward end of the bushing, a motive fluid supply passage communicating with an admission port in the bushing located at a point intermediate the said supply and exhaust ports, a passageway in the wall of the hollowportion of the crank for controlling the distribution of motive fluid to the cylinders, and ports in the crank for exhausting the cylinders through the -hollow portion of the crank.

3. In a rotary tool, the combination of a case having a forwardly extending bore, a fluid actuated motor having a plurality of cylinders radially arranged in the rearward portion of the case, a motive fluid supply passage in the case leading to an admission port at a oint intermediate the length of said bore, uid passages leading from points in said bore located rearwardly of sa1d admission port to the said cylinders, an exhaust port in the case, a valve bushing in said bore having ports registering with said ports in the case, a crank adapted to be driven by said motor and having a hollow portion in said bushin ,said crank also hav- 1ng ports and a tperip eral passage way for controlling the istrlbution of motive fluid to the cylinders and for exhausting the cylinders through the hollow portion of the crank.

4. In a rotary tool, the combination of a case having an enlarged rearward chamber and a forward bore of reduced diameter, a fluid atuated motor having a plurality of radially arranged cylinders extending into said rearward chamber and provided with pistons adapted to be connected to operate a crank, said case having a motive fluid' supply passage leadin to an admission port at a pointA interme iate the length of said smaller bore, motive fluid assages connectingthe cylinders with com ined supply and exhaust ports located at points in the smaller,

bore rearwardly `of the said admission port, an exhaust port in said smaller bore, a. valve bushing in said smaller bore .having ports registering with said ports in the case, a crankhavi 1' hollow rtion `extending throu h sai bushing an provided with a periperal assage way for controlling the supply of uid tothe cylinders, and also provided with ports for exhausting said cylinders through the hollow portion of the crank.

5. In a rotary tool, the combination of a case havlng an enlarged rearward chamber and a forward bore of reduced diameter, a

fluid actuated motor having a plurality of renewable radially arranged cylinders extending into said enlarged rearward cha-1nber, single acting pistons reciprocating in said cylinders and having connecting rods adapted to beconnected to a common crank pin, a motive fluid supply passage in the case eading to an admission port intermediate the length of said smaller bore, motive fluid assages connecting the cylinders to corn-v ined snpgly and exhaust ports located rearwardly o the said admissionport, an exhaust port at the forward end of said smaller bore, a main valve bushing in said smaller bore of the case having ports registering `wlth said combined supply and exhaust ports, and also having an exhaust port at its forward end and an annular interior passage registering with the said admission port in the case, a crank extending through said main valve bushing and'having a crank pin for the connecting rods of the pistons of the motor, bearings for each end of the crank inl In testimony whereof I have signed 'this specification.

. FRANCIS A.. J IMERSON 

